git-format-patch: add a new format.cc configuration variable
[git] / builtin-reflog.c
1 #include "cache.h"
2 #include "builtin.h"
3 #include "commit.h"
4 #include "refs.h"
5 #include "dir.h"
6 #include "tree-walk.h"
7 #include "diff.h"
8 #include "revision.h"
9 #include "reachable.h"
10
11 /*
12  * reflog expire
13  */
14
15 static const char reflog_expire_usage[] =
16 "git-reflog (show|expire) [--verbose] [--dry-run] [--stale-fix] [--expire=<time>] [--expire-unreachable=<time>] [--all] <refs>...";
17 static const char reflog_delete_usage[] =
18 "git-reflog delete [--verbose] [--dry-run] [--rewrite] [--updateref] <refs>...";
19
20 static unsigned long default_reflog_expire;
21 static unsigned long default_reflog_expire_unreachable;
22
23 struct cmd_reflog_expire_cb {
24         struct rev_info revs;
25         int dry_run;
26         int stalefix;
27         int rewrite;
28         int updateref;
29         int verbose;
30         unsigned long expire_total;
31         unsigned long expire_unreachable;
32         int recno;
33 };
34
35 struct expire_reflog_cb {
36         FILE *newlog;
37         const char *ref;
38         struct commit *ref_commit;
39         struct cmd_reflog_expire_cb *cmd;
40         unsigned char last_kept_sha1[20];
41 };
42
43 struct collected_reflog {
44         unsigned char sha1[20];
45         char reflog[FLEX_ARRAY];
46 };
47 struct collect_reflog_cb {
48         struct collected_reflog **e;
49         int alloc;
50         int nr;
51 };
52
53 #define INCOMPLETE      (1u<<10)
54 #define STUDYING        (1u<<11)
55
56 static int tree_is_complete(const unsigned char *sha1)
57 {
58         struct tree_desc desc;
59         struct name_entry entry;
60         int complete;
61         struct tree *tree;
62
63         tree = lookup_tree(sha1);
64         if (!tree)
65                 return 0;
66         if (tree->object.flags & SEEN)
67                 return 1;
68         if (tree->object.flags & INCOMPLETE)
69                 return 0;
70
71         if (!tree->buffer) {
72                 enum object_type type;
73                 unsigned long size;
74                 void *data = read_sha1_file(sha1, &type, &size);
75                 if (!data) {
76                         tree->object.flags |= INCOMPLETE;
77                         return 0;
78                 }
79                 tree->buffer = data;
80                 tree->size = size;
81         }
82         init_tree_desc(&desc, tree->buffer, tree->size);
83         complete = 1;
84         while (tree_entry(&desc, &entry)) {
85                 if (!has_sha1_file(entry.sha1) ||
86                     (S_ISDIR(entry.mode) && !tree_is_complete(entry.sha1))) {
87                         tree->object.flags |= INCOMPLETE;
88                         complete = 0;
89                 }
90         }
91         free(tree->buffer);
92         tree->buffer = NULL;
93
94         if (complete)
95                 tree->object.flags |= SEEN;
96         return complete;
97 }
98
99 static int commit_is_complete(struct commit *commit)
100 {
101         struct object_array study;
102         struct object_array found;
103         int is_incomplete = 0;
104         int i;
105
106         /* early return */
107         if (commit->object.flags & SEEN)
108                 return 1;
109         if (commit->object.flags & INCOMPLETE)
110                 return 0;
111         /*
112          * Find all commits that are reachable and are not marked as
113          * SEEN.  Then make sure the trees and blobs contained are
114          * complete.  After that, mark these commits also as SEEN.
115          * If some of the objects that are needed to complete this
116          * commit are missing, mark this commit as INCOMPLETE.
117          */
118         memset(&study, 0, sizeof(study));
119         memset(&found, 0, sizeof(found));
120         add_object_array(&commit->object, NULL, &study);
121         add_object_array(&commit->object, NULL, &found);
122         commit->object.flags |= STUDYING;
123         while (study.nr) {
124                 struct commit *c;
125                 struct commit_list *parent;
126
127                 c = (struct commit *)study.objects[--study.nr].item;
128                 if (!c->object.parsed && !parse_object(c->object.sha1))
129                         c->object.flags |= INCOMPLETE;
130
131                 if (c->object.flags & INCOMPLETE) {
132                         is_incomplete = 1;
133                         break;
134                 }
135                 else if (c->object.flags & SEEN)
136                         continue;
137                 for (parent = c->parents; parent; parent = parent->next) {
138                         struct commit *p = parent->item;
139                         if (p->object.flags & STUDYING)
140                                 continue;
141                         p->object.flags |= STUDYING;
142                         add_object_array(&p->object, NULL, &study);
143                         add_object_array(&p->object, NULL, &found);
144                 }
145         }
146         if (!is_incomplete) {
147                 /*
148                  * make sure all commits in "found" array have all the
149                  * necessary objects.
150                  */
151                 for (i = 0; i < found.nr; i++) {
152                         struct commit *c =
153                                 (struct commit *)found.objects[i].item;
154                         if (!tree_is_complete(c->tree->object.sha1)) {
155                                 is_incomplete = 1;
156                                 c->object.flags |= INCOMPLETE;
157                         }
158                 }
159                 if (!is_incomplete) {
160                         /* mark all found commits as complete, iow SEEN */
161                         for (i = 0; i < found.nr; i++)
162                                 found.objects[i].item->flags |= SEEN;
163                 }
164         }
165         /* clear flags from the objects we traversed */
166         for (i = 0; i < found.nr; i++)
167                 found.objects[i].item->flags &= ~STUDYING;
168         if (is_incomplete)
169                 commit->object.flags |= INCOMPLETE;
170         else {
171                 /*
172                  * If we come here, we have (1) traversed the ancestry chain
173                  * from the "commit" until we reach SEEN commits (which are
174                  * known to be complete), and (2) made sure that the commits
175                  * encountered during the above traversal refer to trees that
176                  * are complete.  Which means that we know *all* the commits
177                  * we have seen during this process are complete.
178                  */
179                 for (i = 0; i < found.nr; i++)
180                         found.objects[i].item->flags |= SEEN;
181         }
182         /* free object arrays */
183         free(study.objects);
184         free(found.objects);
185         return !is_incomplete;
186 }
187
188 static int keep_entry(struct commit **it, unsigned char *sha1)
189 {
190         struct commit *commit;
191
192         if (is_null_sha1(sha1))
193                 return 1;
194         commit = lookup_commit_reference_gently(sha1, 1);
195         if (!commit)
196                 return 0;
197
198         /*
199          * Make sure everything in this commit exists.
200          *
201          * We have walked all the objects reachable from the refs
202          * and cache earlier.  The commits reachable by this commit
203          * must meet SEEN commits -- and then we should mark them as
204          * SEEN as well.
205          */
206         if (!commit_is_complete(commit))
207                 return 0;
208         *it = commit;
209         return 1;
210 }
211
212 static int expire_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
213                 const char *email, unsigned long timestamp, int tz,
214                 const char *message, void *cb_data)
215 {
216         struct expire_reflog_cb *cb = cb_data;
217         struct commit *old, *new;
218
219         if (timestamp < cb->cmd->expire_total)
220                 goto prune;
221
222         if (cb->cmd->rewrite)
223                 osha1 = cb->last_kept_sha1;
224
225         old = new = NULL;
226         if (cb->cmd->stalefix &&
227             (!keep_entry(&old, osha1) || !keep_entry(&new, nsha1)))
228                 goto prune;
229
230         if (timestamp < cb->cmd->expire_unreachable) {
231                 if (!cb->ref_commit)
232                         goto prune;
233                 if (!old && !is_null_sha1(osha1))
234                         old = lookup_commit_reference_gently(osha1, 1);
235                 if (!new && !is_null_sha1(nsha1))
236                         new = lookup_commit_reference_gently(nsha1, 1);
237                 if ((old && !in_merge_bases(old, &cb->ref_commit, 1)) ||
238                     (new && !in_merge_bases(new, &cb->ref_commit, 1)))
239                         goto prune;
240         }
241
242         if (cb->cmd->recno && --(cb->cmd->recno) == 0)
243                 goto prune;
244
245         if (cb->newlog) {
246                 char sign = (tz < 0) ? '-' : '+';
247                 int zone = (tz < 0) ? (-tz) : tz;
248                 fprintf(cb->newlog, "%s %s %s %lu %c%04d\t%s",
249                         sha1_to_hex(osha1), sha1_to_hex(nsha1),
250                         email, timestamp, sign, zone,
251                         message);
252                 hashcpy(cb->last_kept_sha1, nsha1);
253         }
254         if (cb->cmd->verbose)
255                 printf("keep %s", message);
256         return 0;
257  prune:
258         if (!cb->newlog || cb->cmd->verbose)
259                 printf("%sprune %s", cb->newlog ? "" : "would ", message);
260         return 0;
261 }
262
263 static int expire_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
264 {
265         struct cmd_reflog_expire_cb *cmd = cb_data;
266         struct expire_reflog_cb cb;
267         struct ref_lock *lock;
268         char *log_file, *newlog_path = NULL;
269         int status = 0;
270
271         memset(&cb, 0, sizeof(cb));
272         /* we take the lock for the ref itself to prevent it from
273          * getting updated.
274          */
275         lock = lock_any_ref_for_update(ref, sha1, 0);
276         if (!lock)
277                 return error("cannot lock ref '%s'", ref);
278         log_file = xstrdup(git_path("logs/%s", ref));
279         if (!file_exists(log_file))
280                 goto finish;
281         if (!cmd->dry_run) {
282                 newlog_path = xstrdup(git_path("logs/%s.lock", ref));
283                 cb.newlog = fopen(newlog_path, "w");
284         }
285
286         cb.ref_commit = lookup_commit_reference_gently(sha1, 1);
287         cb.ref = ref;
288         cb.cmd = cmd;
289         for_each_reflog_ent(ref, expire_reflog_ent, &cb);
290  finish:
291         if (cb.newlog) {
292                 if (fclose(cb.newlog)) {
293                         status |= error("%s: %s", strerror(errno),
294                                         newlog_path);
295                         unlink(newlog_path);
296                 } else if (cmd->updateref &&
297                         (write_in_full(lock->lock_fd,
298                                 sha1_to_hex(cb.last_kept_sha1), 40) != 40 ||
299                          write_in_full(lock->lock_fd, "\n", 1) != 1 ||
300                          close_ref(lock) < 0)) {
301                         status |= error("Couldn't write %s",
302                                 lock->lk->filename);
303                         unlink(newlog_path);
304                 } else if (rename(newlog_path, log_file)) {
305                         status |= error("cannot rename %s to %s",
306                                         newlog_path, log_file);
307                         unlink(newlog_path);
308                 } else if (cmd->updateref && commit_ref(lock)) {
309                         status |= error("Couldn't set %s", lock->ref_name);
310                 }
311         }
312         free(newlog_path);
313         free(log_file);
314         unlock_ref(lock);
315         return status;
316 }
317
318 static int collect_reflog(const char *ref, const unsigned char *sha1, int unused, void *cb_data)
319 {
320         struct collected_reflog *e;
321         struct collect_reflog_cb *cb = cb_data;
322         size_t namelen = strlen(ref);
323
324         e = xmalloc(sizeof(*e) + namelen + 1);
325         hashcpy(e->sha1, sha1);
326         memcpy(e->reflog, ref, namelen + 1);
327         ALLOC_GROW(cb->e, cb->nr + 1, cb->alloc);
328         cb->e[cb->nr++] = e;
329         return 0;
330 }
331
332 static int reflog_expire_config(const char *var, const char *value)
333 {
334         if (!strcmp(var, "gc.reflogexpire")) {
335                 if (!value)
336                         config_error_nonbool(var);
337                 default_reflog_expire = approxidate(value);
338                 return 0;
339         }
340         if (!strcmp(var, "gc.reflogexpireunreachable")) {
341                 if (!value)
342                         config_error_nonbool(var);
343                 default_reflog_expire_unreachable = approxidate(value);
344                 return 0;
345         }
346         return git_default_config(var, value);
347 }
348
349 static int cmd_reflog_expire(int argc, const char **argv, const char *prefix)
350 {
351         struct cmd_reflog_expire_cb cb;
352         unsigned long now = time(NULL);
353         int i, status, do_all;
354
355         git_config(reflog_expire_config);
356
357         save_commit_buffer = 0;
358         do_all = status = 0;
359         memset(&cb, 0, sizeof(cb));
360
361         if (!default_reflog_expire_unreachable)
362                 default_reflog_expire_unreachable = now - 30 * 24 * 3600;
363         if (!default_reflog_expire)
364                 default_reflog_expire = now - 90 * 24 * 3600;
365         cb.expire_total = default_reflog_expire;
366         cb.expire_unreachable = default_reflog_expire_unreachable;
367
368         /*
369          * We can trust the commits and objects reachable from refs
370          * even in older repository.  We cannot trust what's reachable
371          * from reflog if the repository was pruned with older git.
372          */
373
374         for (i = 1; i < argc; i++) {
375                 const char *arg = argv[i];
376                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
377                         cb.dry_run = 1;
378                 else if (!prefixcmp(arg, "--expire="))
379                         cb.expire_total = approxidate(arg + 9);
380                 else if (!prefixcmp(arg, "--expire-unreachable="))
381                         cb.expire_unreachable = approxidate(arg + 21);
382                 else if (!strcmp(arg, "--stale-fix"))
383                         cb.stalefix = 1;
384                 else if (!strcmp(arg, "--rewrite"))
385                         cb.rewrite = 1;
386                 else if (!strcmp(arg, "--updateref"))
387                         cb.updateref = 1;
388                 else if (!strcmp(arg, "--all"))
389                         do_all = 1;
390                 else if (!strcmp(arg, "--verbose"))
391                         cb.verbose = 1;
392                 else if (!strcmp(arg, "--")) {
393                         i++;
394                         break;
395                 }
396                 else if (arg[0] == '-')
397                         usage(reflog_expire_usage);
398                 else
399                         break;
400         }
401         if (cb.stalefix) {
402                 init_revisions(&cb.revs, prefix);
403                 if (cb.verbose)
404                         printf("Marking reachable objects...");
405                 mark_reachable_objects(&cb.revs, 0);
406                 if (cb.verbose)
407                         putchar('\n');
408         }
409
410         if (do_all) {
411                 struct collect_reflog_cb collected;
412                 int i;
413
414                 memset(&collected, 0, sizeof(collected));
415                 for_each_reflog(collect_reflog, &collected);
416                 for (i = 0; i < collected.nr; i++) {
417                         struct collected_reflog *e = collected.e[i];
418                         status |= expire_reflog(e->reflog, e->sha1, 0, &cb);
419                         free(e);
420                 }
421                 free(collected.e);
422         }
423
424         while (i < argc) {
425                 const char *ref = argv[i++];
426                 unsigned char sha1[20];
427                 if (!resolve_ref(ref, sha1, 1, NULL)) {
428                         status |= error("%s points nowhere!", ref);
429                         continue;
430                 }
431                 status |= expire_reflog(ref, sha1, 0, &cb);
432         }
433         return status;
434 }
435
436 static int count_reflog_ent(unsigned char *osha1, unsigned char *nsha1,
437                 const char *email, unsigned long timestamp, int tz,
438                 const char *message, void *cb_data)
439 {
440         struct cmd_reflog_expire_cb *cb = cb_data;
441         if (!cb->expire_total || timestamp < cb->expire_total)
442                 cb->recno++;
443         return 0;
444 }
445
446 static int cmd_reflog_delete(int argc, const char **argv, const char *prefix)
447 {
448         struct cmd_reflog_expire_cb cb;
449         int i, status = 0;
450
451         memset(&cb, 0, sizeof(cb));
452
453         for (i = 1; i < argc; i++) {
454                 const char *arg = argv[i];
455                 if (!strcmp(arg, "--dry-run") || !strcmp(arg, "-n"))
456                         cb.dry_run = 1;
457                 else if (!strcmp(arg, "--rewrite"))
458                         cb.rewrite = 1;
459                 else if (!strcmp(arg, "--updateref"))
460                         cb.updateref = 1;
461                 else if (!strcmp(arg, "--verbose"))
462                         cb.verbose = 1;
463                 else if (!strcmp(arg, "--")) {
464                         i++;
465                         break;
466                 }
467                 else if (arg[0] == '-')
468                         usage(reflog_delete_usage);
469                 else
470                         break;
471         }
472
473         if (argc - i < 1)
474                 return error("Nothing to delete?");
475
476         for ( ; i < argc; i++) {
477                 const char *spec = strstr(argv[i], "@{");
478                 unsigned char sha1[20];
479                 char *ep, *ref;
480                 int recno;
481
482                 if (!spec) {
483                         status |= error("Not a reflog: %s", argv[i]);
484                         continue;
485                 }
486
487                 if (!dwim_ref(argv[i], spec - argv[i], sha1, &ref)) {
488                         status |= error("%s points nowhere!", argv[i]);
489                         continue;
490                 }
491
492                 recno = strtoul(spec + 2, &ep, 10);
493                 if (*ep == '}') {
494                         cb.recno = -recno;
495                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
496                 } else {
497                         cb.expire_total = approxidate(spec + 2);
498                         for_each_reflog_ent(ref, count_reflog_ent, &cb);
499                         cb.expire_total = 0;
500                 }
501
502                 status |= expire_reflog(ref, sha1, 0, &cb);
503                 free(ref);
504         }
505         return status;
506 }
507
508 /*
509  * main "reflog"
510  */
511
512 static const char reflog_usage[] =
513 "git-reflog (expire | ...)";
514
515 int cmd_reflog(int argc, const char **argv, const char *prefix)
516 {
517         /* With no command, we default to showing it. */
518         if (argc < 2 || *argv[1] == '-')
519                 return cmd_log_reflog(argc, argv, prefix);
520
521         if (!strcmp(argv[1], "show"))
522                 return cmd_log_reflog(argc - 1, argv + 1, prefix);
523
524         if (!strcmp(argv[1], "expire"))
525                 return cmd_reflog_expire(argc - 1, argv + 1, prefix);
526
527         if (!strcmp(argv[1], "delete"))
528                 return cmd_reflog_delete(argc - 1, argv + 1, prefix);
529
530         /* Not a recognized reflog command..*/
531         usage(reflog_usage);
532 }